The present invention is directed to rotating wheel and tread assemblies for toy building blocks, especially building blocks having stackable interconnection features as well as hinged, interconnecting end features. One such system of building blocks is disclosed in U.S. patent application Ser. No. 621,232, now U.S. Pat. No. 4,606,732 issued to Ronald Lyman. (The entirety of this patent is incorporated herein by reference) This prior art building block system includes a plurality of blocks, each having an array of cylindrical projections extending from one surface, and a like array of socket-like receptacles extending from the opposed surface for stackable interconnection with other blocks. Also, each block includes a pair of hinge arms extending from one end, witha pair of detent knobs formed on the arms, and a pair of recesses formed at the other end of each block and adapted to engage the hinge knobs of like blocks in snap-engaging, pivoting fashion.
As a result of such interconnection features, the blocks may be fashioned into assemblies which are stacked in non-orthogonal fashion, or formed into flexible, bendable, end-to-end chains which describe arcuate formation, curves, and closed loops. Indeed, such loops may be rotatable and movable to create rotating rings, belt-like loops, and the like. Due to the fact that such building block systems are relatively new to the art, there are no wheel assemblies available which exploit the pivotability, mobility, and rotatability of such rings, loops, and other curved block constructions. Clearly there is a need for wheel assemblies adapted to this use, to maximize the creative and recreational potential of hinged building block systems.